Multi-lumen biliary catheter with angled guidewire exit

ABSTRACT

A multi-lumen biliary catheter in which at least one of the lumens ( 14, 16 ) has a side opening port ( 24, 26 ) configured to guide a guidewire ( 32 ) out of that port at an angle to the longitudinal axis of the catheter. Radiopaque marker bands ( 34 ) having different lengths are placed on the distal end of the catheter adjacent the distal openings to facilitate fluoroscopic identification of the distal end orientation in the biliary tract.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a regular utility application that claims the benefit of U.S.Provisional Application No. 60/206,012, filed May 19, 2000 the contentsof which are incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to catheters and guidewires adapted for use inluminal systems of a human body. More specifically, the invention isadapted for use in the biliary tract.

BACKGROUND OF THE INVENTION

Among the procedures involved in diagnosis and treatment of medicalconditions involving the biliary tract are those that require the use ofa guidewire in order to facilitate advancement of a selected catheter toa selected site in the biliary tract. Typically, such procedures areperformed through the working channel of an endoscope. Such proceduresinclude ERCP in which radiopaque contrast liquid is injected intoportions of the biliary tract to enable the physician to visualize theanatomy of the tract as an aid in diagnosis. Among the procedures thatmay be performed are those relating to treatment of an obstructed duct,as may result from tumors, gall stones or other medical conditions.Procedures may be employed to dilate the obstructed region, as with adilatation catheter, or to remove stones, among others. It has becomeincreasingly common to place a stent in the duct so that after theobstruction in the duct has been treated to restore patency, the stentmaintains that patency. Additionally, the physician may wish to placemultiple stents in the region of the branched portions of the biliarytract, even if the adjacent portion of the duct has not been and doesnot need treatment at the time. The decision to place a stent in each ofadjacent branches may be prompted by the difficulty in accessing thesecond branch with a guidewire after a stent has been placed in thefirst branch. It has been found that after a stent has been placed inone branch of the tract in proximity to the juncture of the branches,considerable difficulty can be expected in trying to place a secondguidewire in the other branch. Consequently, it may be preferable toplace both stents at the same time. The present invention facilitatessuch placement as well as provides a versatile catheter usable in othertechniques associated with the biliary tract.

SUMMARY OF THE INVENTION

The advantages of the invention are achieved with a multi-lumencatheter, preferably having three lumens, in which at least one, andpreferably two of the lumens, have distal outlets that are oriented todirect a guidewire out of those lumens along a direction that is angledwith respect to the longitudinal axis of the catheter. One of the lumensin the catheter extends fully to the distal tip of the catheter anddefines a distally facing outlet at the distal tip. Although any of thelumens can be used for the placement of guidewires or for the injectionof contrast media, the lumen(s) with the angled exit port(s) isparticularly useful in a number of situations involving guidewireplacement. For example, should it be difficult to place a guidewire in abiliary branch with the lumen having the distally facing outlet, thecatheter can be adjusted by longitudinal displacement to align an angledguidewire exit port with the entrance to that branch, thereby providinga direct alignment between the exit port and the biliary branch so thatthe guidewire can be aligned and advanced directly into the branch.Additionally, the invention is useful in facilitating placement of twoguidewires in a pair of branches and then removing the catheter, leavingthe two guidewires in place. With the guidewires having been so placed,each can serve as a guide for a stent delivery catheter. By placing bothguidewires in the adjacent biliary branches before placement of eitherstent, it will be possible to achieve easy access to both branches, evenafter a stent has been placed in one of the branches.

It is among the general objects of the invention to provide amulti-lumen biliary catheter that has a high degree of versatility inthat each of the lumens of the catheter may be used either for placementof a guidewire or for transmission of liquids or media between the ductand the proximal end of the catheter. Also among the objects of theinvention is to provide a multi-lumen biliary catheter in which at leastone, and preferably two of the lumens, has an angled exit port at itsdistal end configured to direct a guidewire exiting through the port tobe directed at an angle to the longitudinal axis of the catheter; toprovide a technique by which a plurality of guidewires can be placedwithin the biliary tract to serve in readiness for advancement ofcatheters selectively and independently along one or more of thoseguidewires; and to provide a catheter that facilitates placement of aguidewire in an angled branch of the biliary tree.

DESCRIPTION OF THE DRAWINGS

The foregoing and other objects and advantages of the invention will beappreciated more fully from the following further description thereof,with reference to the accompanying drawings wherein:

FIG. 1A is a diagrammatic illustration of the proximal end of athree-lumen catheter embodying the invention, showing the proximal endin partial stages of manufacture;

FIG. 1B is a diagrammatic illustration of the proximal end of athree-lumen catheter according to one embodiment of the invention.

FIG. 2 is an illustration in perspective of a three-lumen tube that maybe used to fabricate a catheter in accordance with the invention;

FIG. 3 is a cross-sectional diagram of a preferred embodiment of athree-lumen catheter embodying the invention;

FIG. 4 is an enlarged cross-sectional plan view of a three-lumenembodiment of the invention illustrating the configuration of the exitramps at the distal ends of two of the lumens

FIG. 5 is a somewhat diagrammatic isometric illustration of the distalend of the invention;

FIG 6A is a somewhat diagrammatic illustration of the distal end of athree lumen catheter embodying the invention showing a guidewireprojecting at an angle from one of the lumens;

FIG. 6B is an illustration similar to FIG. 6A showing a guidewireprojecting at an angle of emergence of about 25° from the other lumen;and

FIG. 7 is a diagrammatic illustration of the distal end of a three-lumencatheter with radiopaque markers having different lengths.

DETAILED DESCRIPTION

FIGS. 2 and 3 illustrate the preferred configuration of an extrudedpolymeric tube having three lumens. The cross section of the extrudedtube, indicated generally at 10, includes what may be considered as acentral tube 12 and a pair of side tubes 14, 16. The side tubes 14, 16may be formed as a unitary structure with the central tube 12 during theextrusion process. Preferably the extrusion is formed from a polyetherblock amide block co-polymer commercially available under the tradedesignation PEBAX®. A number of PEBAX grades, or blends of PEBAX grades,can be used to achieve the desired shaft stiffness. A preferred grade ofthe block co-polymer is PEBAX 7033. As shown, the maximum transversedimension of the catheter shaft in this embodiment may be about 0.144inches to allow advancement through a 3.8 mm working channel of anendoscope. Preferably, the transverse dimension of the catheter shaft ismaintained at about 0.140 inches to be compatible with endoscopes havingeither 3.7 mm or 3.8 mm working channels.

Each of the tubes 12, 14, 16 defines a lumen, 18, 20, 22, respectively.It may be noted that although the three lumens 18, 20, 22 could beplaced closer together in a more compact pattern, for example, if thecatheter were circular in outer cross section, it is considereddesirable that the side lumens 20, 22 do not lie closely adjacent eachother. Thus, it is preferred that the centers of the side lumens arespaced from each other a distance greater than that between the centrallumen 18 and each of the side lumens 20, 22. Viewed another way, thecenters of the lumens may be considered as defining an isosceles, butnot equilateral, triangle in which a line between the centers of theside lumens 20, 22 would define the hypotenuse. The relative angularorientation of the lumens 18, 20, 22 is as illustrated in FIG. 3.

The proximal end of the catheter may be formed in the manner suggestedin FIGS. 1A and 1B in which a length of the extrusion is separatedlongitudinally to define three separate tubes 12 a, 14 a and 16 a. Aluer fitting 24 may be secured to the proximal end of each of the tubes12 a, 14 a and 16 a, only one of which is shown in FIG. 1 for clarity ofillustration. By providing luer fittings at the proximal end of each ofthe tubes, each of the lumens, 18, 20, 22 can be used selectively for aguidewire or for fluid flow functions. The proximal tubes 12 a, 14 a and16 a may be bound together by shrink tubing 40 (FIG. 1A), or by moldinga proximal trifurcation 42 (FIG. 1B). The center tube 12 a preferably islonger than the side tubes 14 a, 16 a. One of the side legs, such asside leg 14 a shown in FIGS. 1A and 1B, may be provided with a visualmarker 38 at the proximal end. The importance of the visual marker withrespect to the distal end of the catheter is explained below.

The distal end of the catheter is formed by first trimming the distalends of the side tubes 14, 16 so that a length of the central tube 12projects distally beyond the ends of the side tubes 14, 16. FIG. 2illustrates the approximate relative lengths of the tubes 12, 14, and16, although it should be understood that the relative lengths of thedistal end of the device may be varied. The distal ends of the sidetubes 14, 16 are worked, as by heating and molding, so that at leastone, and preferably both, terminate in an angled exit port 24, 26, asindicated in FIGS. 4 and 5. The angled ports 24, 26 may be formed byplacing a suitably oriented mandrel in the distal portion of the lumens20, 22 and then melting and filling the thermoplastic PEBAX or othersuitable polymer to close off the distal opening of the tubes whileforming the side openings 24, 26 with angled ramps 28, 30 that willguide the distal ends of the guidewires out at a desired angle ofemergence with respect to the longitudinal axis of the catheter. FIG. 6Aillustrates a guidewire extended through the lumen of side tube 16 withthe guidewire 32 projecting out of the angled port 26 at the selectedangle of emergence.

To facilitate orientation of the distal end when the catheter is in use,a relatively long radiopaque marker band 34 (shown in FIG. 7) is securedto or formed on the distal end of central tube 12 and a relativelyshorter radiopaque marker band 36 (FIG. 7) is secured to or formed onthe distal end of side tube 14. Radiopaque marker band 36 correspondswith visual marker band 38 on leg 14 a (FIG. 1A). The use of differentlengths of radiopaque marker bands at the distal end of the catheterprovides a means to fluoroscopically ascertain the orientation of thecatheter end relative to the anatomy of the biliary tract or any othertract being evaluated. By having only one side tube labeled with aradiopaque marker at its distal end and having a corresponding visualmarker at its proximal end, the user can distinguish between the twoside tubes and selectively insert a guidewire or inject contrast mediaor other fluid into the desired side tube.

FIG. 6B is similar to FIG. 6A except that it includes preferreddimensional details of the distal tip of the device as well as indicatesan angle of emergence of about 25°. From FIG. 6B it will be appreciatedthat if the catheter were to be advanced and could not itself bedirected into a desired branch, the catheter could be manipulatedlongitudinally to orient the exit port 26 with the entry to that angledbranch. The ramps 24, 26 should be configured to provide a smoothengagement of the distal end of the guidewire with the ramps to assurethat the distal end of the guidewire will not become snagged at the exitports. Additionally, it should be appreciated that although an emergingangle of about 25° is illustrated as being preferred, that angle may bevaried within reasonably acceptable limits including from about 1° toabout 45°.

The invention is versatile in that it can be used in a number ofdifferent modes. In the preferred embodiment, all of the lumens are thesame diameter and can be used with equal facility to receive a guidewireor to communicate fluids between its proximal and distal ends. Thecatheter may be used as a canulating catheter to advance through thepapilla into the biliary tract. It may be used to provide access to abranch duct that cannot otherwise be accessed by aligning an exit portof a side lumen with the entry to that branch and then advancing aguidewire through the catheter so that it emerges from that exit portand passes directly into the desired branch. Moreover, when it isdesired to place a stent in a biliary branch, the invention enablesstent placement to be preceded by placing of two guidewires, one in eachof the two branches, so that after the first stent has been placed, thesecond branch will already have been accessed by a second guidewire,thereby facilitating access of the stent delivery catheter into thesecond branch. Although the catheter has been described with respect toits application to the biliary tree, it should be understood that therelative configuration of the tubes and their respective distal ends canbe used to facilitate advancement of guidewires or fluids into selectedbranches of any branching system of a mammalian body and in particular,a human body.

It should be understood that the foregoing description of the inventionis intended merely to be illustrative thereof and that othermodifications, embodiments and equivalence may be apparent to thoseskilled in the art without departing from its principles.

1. A catheter comprising a shaft extending in a proximal direction froma shaft distal end to a shaft proximal end along a longitudinal axis,the shaft comprising: a first tubular member defining a first lumen, thefirst lumen comprising (i) a first exit port and (ii) a first lumenlongitudinal portion extending in the proximal direction away from thefirst exit port, wherein the first lumen longitudinal portion has acenter as viewed in a cross section perpendicular to the longitudinalaxis; a second tubular member defining a second lumen, the second lumencomprising (i) a second lumen exit port having an axis that forms anangle with the longitudinal axis, (ii) a second lumen longitudinalportion extending in the proximal direction away from the second lumenexit port and extending parallel to the longitudinal axis, and (iii) asecond lumen ramp portion extending in the proximal direction betweenthe second lumen exit port and the second lumen longitudinal portion, soas to smoothly engage a distal end of a second lumen guidewire and avoida snagging of the distal end of the second lumen guidewire at the secondlumen exit port, and wherein the second lumen longitudinal portion has acenter as viewed in the cross section perpendicular to the longitudinalaxis; and a third tubular member defining a third lumen, the third lumencomprising (i) a third lumen exit port having an axis that forms anangle with the longitudinal axis, (ii) a third lumen longitudinalportion extending in the proximal direction away from the third lumenexit port and extending parallel to the longitudinal axis, and (iii) athird lumen ramp portion extending in the proximal direction between thethird lumen exit port and the third lumen longitudinal portion so as tosmoothly engage a distal end of a third lumen guidewire and avoid asnagging of the distal end of the third lumen guidewire at the thirdlumen exit port, and wherein the third lumen longitudinal portion has acenter as viewed in the cross section perpendicular to the longitudinalaxis; wherein the first lumen extends distally beyond a distal end ofthe second lumen, wherein a first imaginary line connecting the centerof the second lumen longitudinal portion and the center of the thirdlumen longitudinal portion is longer than each of a second imaginaryline connecting the center of the first lumen longitudinal portion tothe center of the second lumen longitudinal portion and a thirdimaginary line connecting the center of the first lumen longitudinalportion to the center of the third lumen longitudinal portion, andwherein a first outer cross sectional thickness of the shaft measuredalong a line arranged perpendicular to the first imaginary line is lessthan a second outer cross sectional thickness of the shaft measuredparallel to the first imaginary line.
 2. A catheter as defined in claim1, wherein each of the second lumen longitudinal portion and the thirdlumen longitudinal portion have a circular cross section as viewed inthe cross section perpendicular to the longitudinal axis.
 3. A catheteras defined in claim 1 further comprising (i) a first radiopaque markerband having a first length on a distal end of the first tubular member,(ii) a second radiopaque marker band having a second length on a distalend of the second tubular member, and (iii) no radiopaque marker on thethird tubular member.
 4. A catheter as defined in claim 3 furthercomprising a visual marker on a proximal end of the second tubularmember.
 5. A catheter as defined in claim 1, wherein the second outercross sectional thickness of the shaft is less than or equal to about0.144 inches to allow advancement through a 3.8 mm working channel of anendoscope.
 6. A catheter as defined in claim 1, wherein a base wall ofthe second lumen ramp portion and a distal edge of the second lumen exitport define a second guidewire angle of emergence from about 1° to 45°from the longitudinal axis.
 7. A catheter as defined in claim 6, whereina base wall of the third lumen ramp portion and a distal edge of thethird lumen exit port define a third guidewire angle of emergence fromabout 1° to 45° from the longitudinal axis.
 8. A catheter as defined inclaim 1 further comprising a shrink tube encircling the first tubular,the second tubular member, and the third tubular member along a portionof the shaft.
 9. A catheter as defined in claim 1 wherein the shaft isformed of a block co-polymer.
 10. A catheter as defined in claim 9,wherein the block co-polymer is a grade or a blend of grades ofpolyether block amides.
 11. A catheter comprising a shaft extending in aproximal direction from a shaft distal end to a shaft proximal end alonga longitudinal axis, the shaft comprising: a first tubular memberdefining a first lumen, the first lumen comprising (i) a first exit portand (ii) a first lumen longitudinal portion extending in the proximaldirection away from the first exit port and extending parallel to thelongitudinal axis, wherein the first lumen longitudinal portion has acenter as viewed in a cross section perpendicular to the longitudinalaxis; a second tubular member defining a second lumen, the second lumencomprising (i) a second lumen exit port having an axis that forms anangle with the longitudinal axis, (ii) a second lumen longitudinalportion extending in the proximal direction away from the second exitport and extending parallel to the longitudinal axis, and (iii) a secondlumen ramp portion extending between the second lumen exit port and thesecond lumen longitudinal portion, wherein a base wall of the secondlumen ramp portion, as viewed in a cross section bisecting the secondlumen exit port and extending along a center longitudinal axis of the ofthe second lumen longitudinal portion, extends in the proximal directionfrom a distal edge of the second lumen exit port to the second lumenlongitudinal section so as to smoothly engage a distal end of a secondlumen guidewire and avoid a snagging of the distal end of the secondlumen guidewire at the second lumen exit port, wherein the second lumenlongitudinal portion has a center as viewed in the cross sectionperpendicular to the longitudinal axis; and a third tubular memberdefining a third lumen, the third lumen comprising (i) a third lumenexit port having an axis that forms an angle with the longitudinal axis,(ii) a third lumen longitudinal portion extending in the proximaldirection from the third lumen exit port and parallel to thelongitudinal axis, and (iii) a third lumen ramp portion extendingbetween the third lumen exit port and the third lumen longitudinalportion, wherein a base wall of the third lumen ramp portion, as viewedin a cross section bisecting the third lumen exit port and extendingalong a center longitudinal axis of the third lumen longitudinalportion, extends in the proximal direction from a distal edge of thethird lumen exit port and the third lumen longitudinal portion so as tosmoothly engage a distal end of a third lumen guidewire and avoid asnagging of the distal end of the third lumen guidewire at the thirdlumen exit port, wherein the third lumen longitudinal portion has acenter as viewed in the cross section perpendicular to the longitudinalaxis; wherein the first lumen extends distally beyond a distal end ofthe second lumen, wherein a first imaginary line connecting the centerof the second lumen longitudinal portion and the center of the thirdlumen longitudinal portion is longer than each of a second imaginaryline connecting the center of the first lumen longitudinal portion tothe center of the second lumen longitudinal portion and a thirdimaginary line connecting the center of the first lumen longitudinalportion to the center of the third lumen longitudinal portion, andwherein a first outer cross sectional thickness of the shaft measuredalong a line arranged perpendicular to the first imaginary line is lessthan a second outer cross sectional thickness of the shaft measuredparallel to the first imaginary line.
 12. A catheter as defined in claim11, wherein each of the second lumen longitudinal portion and the thirdlumen longitudinal portion have a circular cross section as viewed inthe cross section perpendicular to the longitudinal axis.
 13. A catheteras defined in claim 11 further comprising (i) a first radiopaque markerband having a first length on a distal end of the first tubular member,(ii) a second radiopaque marker band having a second length on a distalend of the second tubular member, and (iii) no radiopaque marker on thethird tubular member.
 14. A catheter as defined in claim 13 furthercomprising a visual marker on a proximal end of the second tubularmember.
 15. A catheter as defined in claim 11, wherein the second outercross sectional thickness of the shaft is less than or equal to about0.144 inches to allow advancement through a 3.8 mm working channel of anendoscope.
 16. A catheter as defined in claim 11, wherein a base wall ofthe second lumen ramp portion and a distal edge of the second lumen exitport define a second guidewire angle of emergence from about 1° to 45°from the longitudinal axis.
 17. A catheter as defined in claim 16,wherein a base wall of the third lumen ramp portion and a distal edge ofthe third lumen exit port define a third guidewire angle of emergencefrom about 1° to 45° from the longitudinal axis.
 18. A catheter asdefined in claim 11 further comprising a shrink tube encircling thefirst tubular, the second tubular member, and the third tubular memberalong a portion of the shaft.
 19. A catheter as defined in claim 11,wherein the shaft is formed of a block co-polymer.
 20. A catheter asdefined in claim 19, wherein the block co-polymer is a grade or a blendof grades of polyether block amides.